Expandable spout for bag filling machine



Dec. 27, 1966 E. M. LAU

EXPANDABLE SPOUT FOR BAG FILLING MACHINE 4 Sheets-Sheet l Filed Nov. 16, 1964 ,M ffii Dec. 27, 1966 E. M. LAU

EXPANDABLE SPOUT FOR BAG FILLING MACHINE 4 Sheets-Sheet 2 Filed NOV. 16, 1964 Dec. 27, 1966 E. M. LAU

EXPANDABLE SPOUT FOR BAG FILLING MACHINE 4 Sheets-Sheet 5 Filed NOV. 16, 1964 Dec. 27, 1966 E, M LAU 3,294,127

EXPANDABLE SPOUT FOR BAG FILLING MACHINE Filed Nov. 16, 1964 4 Sheets-Sheet 4 United States Patent() 3,294,127 EQANDABLE SPOUT FOR BAG FILLING MACHINE Erwin M. Lau, Dolton, Ill., assignor to Black Products Co., Chicago, Ill., a corporation of Illinois Filed Nov. 16, 1964, Ser. No. 411,469 7 Claims. (Cl. 141-68) This invention relates to an expandable spout for bag filling machines, and is particularly well adapted for use in a bag filling machine of the fiuidizing type, as shown in my Patent No. 2,936,994, granted May 17, 1960.

The problem of providing a seal between the spout and the valve of a bag has been recognized in Titchenal Patent No. 2,955,796, to which reference is hereby made. Briefly, the bag, or its valve, which is a tubular sleeve type of arrangement, should be enough larger than the spout diameter so` as to facilitate placement of the bag. However, clearance between the two permits air to escape from the bag into the surrounding atmopshere. When the material being packed is a powder, there is much dust suspended in the air. This dusty environment, in addition to being unpleasant and messy, is a health hazard. This is particularly true of machines of the fluidizing type for the reason that the fiuidized material passing into the bag has a great deal of air entrapped in it. Therefore, it has been proposed to provide an inflatable sleeve around the spout which can be inflated after the bag has been positioned in order to seal off the clearance between the bag Valve and the spout.

However, this infiatable sleeve arrangement is unsatisfactory in certain respects. For instance, if the inflating mechanism is actuated when a bag is not on the spout, it is likely to blow out or explode, injuring the operator who is standing right next to it. Thus, the prior device is a distinct safety hazard.

Another objection to the prior device is that both the interior and the exterior of the filling tube or spout should be a smooth surface without any abrupt interruptions or changes in diameter. In the prior device, the inflatable sleeve constitutes an enlargement in the external diameter of the spout which interferes with rapid bag placement. In many instances, it is also a specially moulded rubber product, which represents an additional element of cost.

It is an object of the present invention to provide an expandable spout in which the sleeve is mechanically expanded. This eliminates the possibility of blowout.

Another object is to provide a spout and sleeve con- Y struction which is of substantially uniform external diameter, when in contracted position, so as to facilitate bag placement.

According to my invention, I provide an expander device which is in the form of a shell disposed between the filling tube and the sleeve, and the arrangement is such that there is a pivoting or hinging action incident to the expanding operation, but the parts are constructed and arranged in such a manner that no pivot or hinge means is required at the front end of the shell. Thus, it is possible to provide a filling tube, the internal surface of which is uninterrupted by pivot pins which would necessarily have to penetrate the wall of the filling spout, and cause a build up of material which would interfere with rapid bag filling action.

Furthermore, my invention does not require, as a sleeve, a specially moulded rubber product. Rather, an ordinary piece of rubber tubing will suffice.

Also, by using a mechanically expanding sleeve, even though it may be actuated by an air cylinder, it is possible to eliminate certain complexities of the air supply system customarily used in a spout of the inflatable sleeve type.

Other objects, features and advantages of my inven- 31,294,127 Patented Dec. 27, 1966 lCC tion will become apparent as the description proceeds.

With reference now to the drawings in which like reference numerals designate like parts:

FIG. l shows an elevation of a spout embodying my invention;

FIG. 2 is a sectional elevation of the same;

FIG. 3 is a vertical section taken along line 3--3 o FIG. 1;

FIG. 4 is a vertical section taken along line 4-4 of FIG. 2;

FIG. 5 is a view similar to FIG. 1 but showing the sleeve in its expanded position;

FIG. 6 is a view similar to FIG. 5, but with the sleeve shown in section so that the expander device may be shown in elevation;

FIG. 7 is a vertical section taken along line 7 7 of FIG. 6;

FIG. 8 is an enlarged section similar to FIG. 6, with the sleeve omitted to show the clearance;

. FIG. 9 is a front elevation of a modified expander device, the rubber sleeve being removed for the purpose of clarity;

FIG. l0 is a view similar to FIG. 9 but showing the same in changed position;

FIG. l1 is a side elevation of FIG. 10;

FIG. 12 is a plan view taken along line 12-12 of FIG. 11, but showing the expander device in partially opened position; and

FIG. 13 is a vertical section similar to FIG. 4, taken along line 13-13 of FIG. 11, but also showing the rubber sleeve.

The spout 10 comprises a filling tube 11 having a mounting flange 12 by means of which the spout may be mounted on a part of the scale mechanism 13 of a bag filling machine such as that shown in my aforesaid patent, and the scaling mechanism of which member 13 is a part, can be either as shown in the aforesaid patent, or of the type shown in my Patent No. 3,133,608 granted May 19, 1964.

A rubber sleeve 14 surrounds the filling tube 11. kThe expander device 15 comprises a shell 16 which is disposed betweeu the rubber sleeve 14 and the filling tube 11, together with a base portion 17 which is in the form of a block as shown in FIG. 3.

The expander device 15 is pivotally connected to a yoke 18 by means of pivot pins 19, as shown in FIG. 3, and the yoke 18 is mounted on the piston 20 of an air cylinder 21. The air cylinder is suitably mounted on the member 13 on which the spout 10 is also mounted.

In operation, when the air cylinder 21 is energized, the expander device moves downwardly into the FIG. 5 position, thus expanding the sleeve 14.

A feature of my invention is that the rubber sleeve 14 cooperates with the free end 22 of the shell 16 to provide a hinging action which does not require the use of any pivot pins. Thus the internal surface of the filling tube 11 is smooth and uninterrupted by pivot pins or the like. the outer surface of the filling tube 11 so that it is free for a certain amount of sliding movement; nevertheless the resilience of the rubber sleeve 14 maintains the free end 22 in contact with the filling tube surface at all times.

y As best shown in FIG. 2, the filling tube 11 has a portion 23 of reduced diameter which extends over the greater part of its length. The rubber sleeve 14 overlies this reduced portion so that the over all outer diameter of the spout 10 will be substantially uniform, thus facilitating bag placement.

Tihe front end of the rubber sleeve 14 is secured to the filling tube by means of a clamp ring 24, the outer diameter of which is substantially the same as the outer In other words, the free end 22 loosely engages i 3 diameter of the front or thick portion 25 of the filling tube 11.

However, the inner diameter of the clamp ring 24 is sufficiently larger than the outer diameter of the reduced portion 23 as to provide a clearance 26 which, although of smaller dimensions than the normal wall thickness of the rubber sleeve 14, is nevertheless sufiicient to accommodate the same if the sleeve has previously been stretched.

In other words, as shown in FIG. 2, the over all outer diameter of the spout is substantially uniform from the front end back to the yoke 18 and base portion 17. There are slight variations due to the thickness of the shell 16 which is interposed between the sleeve 14 and lche reduced portion 23, but the over all impression is one of substantial-ly uniform diameter. Thus there is no obstruction which interferes with rapid bag placement.

The parts 11, 14 and 24 may be assembled by taking a section of tubing which is somewhat longer than what is ultimately required, and stretching it axially over the filling tube 11.

The operation may be facilitated by using a hose clamp to temporarily secure t-he front end rubber sleeve to the front portion 25 of the filling tube. This leaves both hands free to manipulate the tensioned rear end of the sleeve, and to effect the tensioning or drawing out of the sleeve so that its wall thickness is reduced by somewhat more than 50%. This permits the operator to slip the clamp ring 24 over both the reduced portion 23 and the sleeve 14. In this position of parts, it will be understood that the rear end of the sleeve 14 extends considerably beyond the rear end of the filling tube 11, and permits the operator to thread the sleeve 14 through the clamp ring 24. After sleeve 14 is thus maintained in its extended and tensioned position,` it will be seen that it is possible to move the ring forwardly, particularly if the sleeve has been lubricated with a soap solution. The ring may thus be readi-ly `moved forwardly until further movement is prevented by the increase in sleeve diameter represented by the shoulder 27 which separates the front portion 25 from the reduced portion 23 of the filling tube.

Then the rear end of the sleeve 14 is released which causes the same to expand in thickness. The front end of the rubber tubing is then trimmed at the shoulder 27, and the rear end is trimmed to its final length as shown in FIG. 2. By suitable manipulation of the parts so as to maintain a certain amount of tension on the sleeve, it is possible to cause the front end of the sleeve 14 to contract or withdraw entirely within the confines of the clamp ring 24, as shown in FIGS. 2 and 6, so that there will be no rubber flange projecting outwardly at the shoulder 27.

After trimming, then the expander device 15 can be readily inserted between the sleeve 14 and the filling tube 11, and then the remaining parts assembled to each other.

The shell 16 may be fabricated by splitting a short length of thin wall tubing, the rear end being received within the saddle of the base portion 17 and welded thereto.

In the embodiment shown, the rubber sleeve 14 has a wall thickness of slightly more than one-sixteenth of an inch, and the clamp ring 24 has a wall thickness of slightly less than one-sixteenth of an inch, and the clearance 26 is substantially one thirty-second of an inch.

FIG. 5 shows a bag 28 in broken lines which lhas a tubular portion 29 which constitutes the valve or flap thereof.

After the valve 29 has been placed over the spout 10, the air cylinder 21 is actuated to expand the sleeve 14 as shown in FIGS. 5 and 6. Thus, the sleeve engages the rear edge of the tubular valve portion 29, and stretches or deforms the same so that the rear edge of the tubular portion conforms itself to the oval shape of the sleeve when expanded, as shown in FIG. 7. Thus an effective seal is provided which prevents the escape of powder laden air from the bag into the surrounding atmosphere.

I have found not only that the sealing action is effective for this purpose, but in some instances the engagement is sufficiently firm as to enable me to dispense with the usual bag clamp.

In the case of porous wall bags, the expander device is not released until the air pressure within the bag has had an opportunity to escape through the bag waill. However, the present invention can be used in connection with a self venting spout, of the general type shown in my Patent 3,102,561, granted September 3, 1963, so as to enable the use of my expanding spout with moisture barrier bags, the walls of which are not Iporous. Also, my invention is useful in connection with types of feeding arrangements other than the fiuidizing type, although the need for a sealing arrangement is greater with the fiuidizing type of material feed than it is with the auger type or the paddle type.

FIGS. 9 to 13 show a modified expander device 30 which comprises two shells 31 located at the sides of the spout 10" instead of a single` shell 16 located below the spout, as in FIGS. 1 to 8. The two-shell arrangement makes a better seal with the pasted valves of pasted bags than does the single shell arrangement. Also, it accommodates itself to a greater latitude in sizeof valve opening than does the single shell device.

In the modification, the base portion of each shell 31 is in the form of a lug 32. The actuating means includes an air cylinder 21 mounted on the scale part or plate 13 by means of a bracket 33. Pillars 34 extend forwardly from the bracket 33. Levers 35 are pivotally mounted on the pillars 34 and are connected to the lugs 32 by links 36 and pins 37. Thus, a spreading of the levers 35 moves the shells 31 outwardly to expand the sleeve 14', in substantially the same manner as described in the single shell embodiment.

A bracket 38 is mounted on the lower end of the piston 39 of the air cylinder 21. Thrust links 40 extend between the bracket 38 and each of the levers 35. Thus, actuation of the air cylinder 21', causes a spreading of the levers 35 as shown in FIG. 10.

To avoid a tearing of the valve which can occur due to the fact that the force exerted by the air cylinder 21 and the linkage may be greater than the strength of the paper and the pasted or stitched seams, adjustable stop means are provided to limit the throw of the piston 39. As shown in FIGS. 9 and 11, a horizontal lug 41 extends forwardly from the bracket 33 and carries a stop screw 42 which is threaded therethrough. Suitable adjustment of the stop screw will limit the throw of the piston 39 and of the linkage so that the limiting position of the two shells 31, as shown in FIG. 12, will approximate the size of the opening of the bag valve 29. Thus, a tight seal may be provided without encountering the risk of tearing. Similarly, the actuating mechanism can be adjusted for different sizes of bag valves.

The two-shell modification provides a symmetrical arrangement in which the angular extent of expansion (angle a in FIG. l2) may be 25 or more without encountering any tendency wherein the bag would be carnmed off of the spout. Thus a very substantial latitude in size of bag opening can be accommodated without detracting from the effectiveness of the seal which is provided.

Although only preferred embodiments of my invention have been shown and described herein, it will be understood that various changes and modifications may be made in the constructions shown without departing from the spirit of my invention as pointed out in the appended claims.

I claim:

1. An expandable spout for a bag filling machine comprising a filling tube, a flexible resilient sleeve surrounding said filling tube, an expander device disposed between said sleeve and said lling tube, and means for moving one end of said expander device away from said filling tube against the resilience of said sleeve to engage the valve of a bag which has been tted over said spout.

2. An expandable spout as claimed in claim 1 in which said expander device comprises a shell and a base portion, said base portion being disposed beyond the rear edge of said sleeve, said shell extending forwardly of said base portion between said sleeve and said lling tube, and the front end of said shell being free, the resilience of said sleeve maintaining the free front end of said shell in contact with the outer surface of said lling tube during the expanding movement of the rear end thereof.

3. An expandable spout as claimed in claim 2 which includes a yoke pivotally connected to said base portion, and an air cylindei for actuating said yoke.

4. A11 expandable spout for a bag lling machine as claimed in claim 1 in which said lling tube has a front portion of a given outer diameter, and rear and intermediate portion of reduced outer diameter, a clamp ring having an outer diameter substantially the same as the outer diameter of said front portion, the front end of said sleeve being conned between said clamp ring and the front end of said reduced portion, the clearance between said clamp ring and said reduced portion being less than the normal wall thickness of said sleeve.

5. An expandable spout as claimed in claim 1 in which said expander device comprises a pair of oppositely disposed shells located at either side of said lling tube and overlying same, each shell having an arcuate length of substantially in a direction perpendicular to the axis of said filling tube.

6. An expandable spout as claimed in claim 1 in which said expander device comprises a pair of oppositely disposed shells overlying said lling tube, a supporting bracket, an air cylinder mounted on said bracket, a pair of levers pivotally mounted at one end on said bracket, means connecting the other end of said levers to the rear end of each shell, said air cylinder including a piston, and link means connecting each lever with said piston for spreading said levers and expanding said shells, the front end of each shell being free.

7. An expandable spout as claimed in claim 6 in which said bracket includes a forwardly extending lug, and a stop screw mounted in said lug for engagement with said piston to limit the throw of said piston and the expansion of said shells.

No references cited.

LAVERNE D. GEIGER, Primary Examiner.

H. S. BELL, Assistant Examiner. 

1. AN EXPANDABLE SPOUT FOR A BAG FILLING MACHINE COMPRISING A FILLING TUBE, A FLEXIBLE RESILIENT SLEEVE SURROUDING SAID FILLING TUBE, AND EXPANDER DEVICE DISPOSED BETWEEN SAID SLEEVE AND SAID FILLNG TUBE, AND MEANS FOR MOVING ONE END OF SAID EXPANDER DEVICE AWAY FROM SAID FILLING TUBE AGAINST THE RESILIENCE OF SAID SLEEVE TO ENGAGE THE VALVE OF A BAG WHICH HAS BEEN FITTED OVER SAID SPOUT. 